Capacitance of Nanoporous Carbon-Based Supercapacitors Is a Trade-Off between the Concentration and the Separability of the Ions

摘要: Nanoporous carbon-based supercapacitors store electricity through adsorption of ions from the electrolyte at surface electrodes. Room temperature ionic liquids, which show largest ion concentrations among organic liquid electrolytes, should in principle yield larger capacitances. Here, we by using electrochemical measurements that capacitance is not significantly affected when switching a pure to conventional same species. By performing additional molecular dynamics simulations, interpret this result as an increasing difficulty separating opposite charges they are more concentrated, is, absence solvent screens Coulombic interactions. The charging mechanism consistently changes with concentration, counterion diluted exchange liquid. Contrarily capacitance, in-pore diffusion coefficients largely depend on composition, noticeable slowing